If you have seen comparisons between Lumia 920, Lumia 925, Lumia 928 , iPhone 5 and others you will find it difficult to find difference between images unless you zoom in, crop and then compare. Then I remember when 808 pureview was launched, many tech sites were quick to say that you can hardly do anything better with 808 than zooming in....and some even suggested iPhone 5 is better. Now, it was only later when it was realized that why 5 MP images from 808 were better than 8 MP images from other smartphones. Because you can in first look find out difference in sharpness, clarity and level of details and 808 images will always look better. I find similar difference here as well and Lumia 1020 look much better than Lumia 920 images in sharpness and details.
Anyways, I will suggest the poster to click 5 Mp image with Lumia 1020 and then compare it with Lumia 920 images as with 5 MP images only you see advantage of oversampling!!